Means for automatically opening and closing a compressor intake



June 12, 195] M. A. LIPKAU 2,556,

MEANS FOR AUTOMATICALLY OPENING AND CLOSING A COMPRESSOR INTAKE FiledSept. 30, 1946 I 2 Sheets-Sheet 1 Mex M4 5 June 12, 1.951 M. A. LIPKAU2,556,623 MEANS FOR AUTOMATICALLY OPENING AND v CLOSING A COMPRESSORINTAKE Filed Sept. 30, 1946 2 SheetsSheet 2 Fig: 5.

fiaximz'll'ano- H. Lip/(ad Patented June 12,1951

MEANS FOR AUTOMATICALLY OPENING AND CLOSING A COMPRESSOR INTAKEMaximiliano Alvarez Lipkau, Barcelona, Spain Application September 30,1946, Serial No. 700,232 In Spain March 26, 1946 4 Claims.

The present invention relates to a device or apparatus for automaticallyefiecting the opening and closing of the admission of atmospheric airdirectly into a compressor or the like, or into a compressor working asa vacuum machine, or working in both capacities at the same time, independence upon the raised pressure or partial vacuum established in areservoir communicating with the device. Such a device is fitted withoutmodifying the compressor in any way, all that is, necessary being tocouple it to the inlet connection of the compressor, leaving the usualvalves of the compressor as they were. When applied to a machine workingas a compressor properly so called it has the result that the latter,without ceasing to function, discontinues compressing air into thestorage vessel when the pressure therein reaches its maximum, andresumes compression when it falls to its minimum, the said maximum andminimum being adjustable. Similarly, when applied as a modification to acompressor working as an exhaust pump or vacuum machine, or to acompressor operating simultaneously as a compressor and as a vacuummachine, it maintains, in a vessel provided for the purpose, apredetermined degree of vacuum fixed between two limits, a maximum and aminimum, the values of which are adjustable.

One important problem resides in the desirability of ensuring that theclosing and opening of the admission are eifected suddenly, withoutequilibrium of forces being produced, which would keep the valvefloating. This has been solved by utilising the inherent suction forceof the compressor, as hereinafter explained.

Essentially the device in question comprises a diaphragm'or likeresilient element or a piston or other displaceable element, or someelement equivalent thereto in its action, combined, with mechanicalinterengagement or dependence, with a valve which opens and closes theadmission of atmospheric air. This diaphragm, piston or equivalentelement forms the terminus of a communication with the storage vesselannexed to the compressor in which the compressed air is stored, if thecompressor is working as a compressor properly so called, or with theannexed reservoir in which-the vacuum is created, if the compressor ismounted or is being utilised as an exhaust pump. The device comprisestwo chambers: one constituting the inlet connection for the admission ofatmospheric air to the compressor, this chamber being opened and closedby the valve to which reference is made above, and the other closedpermanently on one side by the resilient diaphragm or piston orequivalent element, and communicating on the other side with thereservoir, either of vacuum or of compressed air.

In the device in question, the valve and the diaphragm or piston areinterconnected or mechanically dependent on one another preferably intandem, and are mounted in such a way that whether there is or is notany axial clearance which leaves the valve a certain amount of intrinsicmobility, the latter is guided and controlled by a rod or like memberwhich follows the movements of the diaphragm or piston. Differenteffective areas are provided for the valve and for the diaphragm orpiston, for the purpose of obtaining a differential pressure action, orelse a spring is provided which acts upon the said elements; orpreferably both arrangements are adopted in combination with oneanother.

To enable the invention to be more clearly understood, reference is madeto the accompanying diagrammatic drawings, in which:

Figure 1 shows in longitudinal section a form of the device suitable formounting on a compressor functioning as such;

Figure 2 is a sketch in outside elevation of an installationincorporating the device;

Figure 3 shows in longitudinal section a form of the device suitable formounting on a compressor operating as a vacuum machine; and

Figure 4 is a cross section on the line CC in either Figure 1 or Figure3.

In its application to a compressor properly so called, as illustrated byway of example in Figures l, 2 and 4, the device consists of a valve land a resilient diaphragm 4, united with one another in tandem by a rod5. The valve may be so mounted as to have a certain amount of'lostmotion or axial play, but this is not essential. The valve opens andcloses the chamber A, which constitutes the inlet connection foratmospheric air, and communicates at C with the compressor suctionspigot. The diaphragm 4 (for which a piston displaceable in acorresponding cylinder may be substituted if desired) divides thechamber B into two compartments, one of which communicates by a pipe orduct 6 with a storage reservoir for compressed air marked D in Figure 2,the valve and diaphragm device as a whole being marked V in that figure.The surface area of the valve I is different from that of the diaphragm4, and a spring 2 has been provided, which bears against a washer 3,secured to the stem 5 of the valve l, the position of the washer beingadjustable by screwing it along a thread 3 on the valve stem 5. Theother end of the spring 2 rests against a fixed ledge projecting inwardsfrom the frame of the body or cage 8 of the device. The diaphragm 4 issecured to the rod 5 by means of washers l and a nut 9. The pipe 6 iscoupled to the device by a union i2. A cylindrical filter ll, retainedby a covering 10, precludes the entrance of dust and extraneousmaterials to the compressor intake.

This device operates in the following manner: When the upper limit ormaximum pressure is reached in the storage reservoir D of compressedair, and therefore in the lower compartment oi the chamber B, which isin open communication therewith, the diaphragm 4 bulges upwards, therebydisplacing the rod 5 and the Valve i, which therefore approaches themouth of the chamber A, after the resistance of the spring 2 has beenovercome. As the valve i approaches the mouth of the chamber A it isalso urged towards it by the suction, and moves quickly on to its seat,this action being facilitated by the axial play that may be providedbetween the valve and the diaphragm. When the valve bears against itsseat it closes the admission of atmospheric air to the compressor, andis thereafter retained in this position by the vacuum in the chamber A.

When the pressure in the storage reservoir falls to the lower limit, anaction opposite to that described above is produced, since the diaphragm4 curves downwards, and drags down with it the rod 5 and the valve I.When once the withdrawal of the valve from the mouth of the chamber Ahas been initiated the same separates therefrom promptly, since apressure approaching atmospheric pressure becomes established almostimmediately in the chamber A, where previously there was a vacuum. Thepassageway now remains open until the cycle of operations hereinbeforedescribed recommences.

In its application to a compressor operating as a vacuum pump the deviceis supplemented, asillustrated in Figure 3 by a branch pipe or duct l5leading directly from the vacuum reservoir tov the suction spigot. Inthe pipe i5 is interposed a spring-controlled non-return valve 13. Inother respects the device is analogous to that described for thepreceding case, the various elements being denoted in Figure 3 by thesame reference numerals as in Figure l, with the addition of a tick oraccent mark. The difference resides in the abovementioned conduit it;with the stop valve l3, and in the fact that the spring 2- of Figure 3acts in a direction opposite to that of the spring 2 in Figure 1,tending in the present case tokeep the valve i pressed mouth of thechamber A. This chamber A, and likewise the branch conduit E5 in thepart beyond the non-return valve 13, communicate with the suction intakeC. The chamber B, and the part of the branch conduit preceding the valvel3, communicate with the reservoir in which a predetermined degree ofvacuum is to be maintained, between limits adjusted by means of a nut 3,which can be screwed along a thread-- ed portion of the valve rod 5'.

This form of the device functions in the foilowing manner: When thehighest vacuum (or in other words the lowest sub-atmospheric pressure)has been reached in the vacuum reservoir, the diaphragm 4 curves in thedirection or" the arrow i i in Figure 3, or an equivalent piston slidesin that direction, and draws down with it the valve 1, thereby openingthe vacuum cham- 4 her A to atmospheric pressure, which reaches theintake C, and also helps to impel the valve downwards. The free flow ofatmospheric air through the chamber A to the intake C allows the valve13 to close under the action of its own spring. When on the contrary thelower limit of vacuum is reached (or in other words the maximumsub-atmospheric pressure) in the vaccuum storage reservoir, the spring2' is strong enough to counteract the action of the vacuum exerted uponthe diaphragm 5, and the valve i approaches the mouth of the chamber A,being then suddenly attracted thereto by the growing suction in thechamber A, this action being assisted as before by the axial play of thevalve if such be provided. The valve then shuts off the admission, andis held firmly upon its seat by the vacuum then produced in the chamberA by the compressor, which then takes in air through the branch conduit15 from the vacuum reservoir, the non-return valve l3 openingautomatically against the action of its closing spring.

The construction and operation of two embodiments of the invention havebeen described in detail, but it must be borne in mind that the detailsmay differ in practice from those that have been set forth andillustrated by way of example.

I claim:

1. For use in conjunction with a compressor adapted to be operated as anexhaust pump and with a vacuum reservoir, a suction nozzle through whichthe exhaust pump draws in air, a pipe connecting the vacuum reservoirwith the suction nozzle, an inlet branched on to the said pipe, throughwhich atmospheric air can pass directly to the said suction nozzle, avalve for opening and closing the said inlet, an element movable inresponse to air pressure, the said movable element being mechanicallycoupled to the valve to control its opening and closing, the side of thepressureresponsive element nearer to the valve being open to atmosphericpressure, and a duct establishing communication between the other sideof the pressure-responsive movable element and the interior of thereservoir.

2. For use in conjunction with a compressor adapted to be operated as anexhaust pump and with a vacuum reservoir, a suction nozzle through whichthe exhaust pump draws in air, a pipe con-' necting the vacuum reservoirwith the suction nozzle, a spring-controlled non-return valve in thesaid pipe to prevent fluid flowing therethrough towards the reservoir,an inlet branched on to the said pipe between the said non-return valveand the suction nozzle, through which inlet atmospheric air can passdirectly to the suction nozzle, a valve for opening and closing the saidinlet, an element movable in response to air pressure, the said movableelement being mechanically coupled to the valve to control its openingand closing, the side of the pressure-responsive element nearer to thevalve being open to atmospheric pressure, a, duct establishingcommunication between the side of the pressure-responsive element remotefrom the valve and the interior f the reservoir and a spring tending toclose the valve against the suction of the reservoir pressure actingupon the movable element.

3. For use in conjunction with a compressor adapted to be operated as anexhaust pump and with a vacuum reservoir, a suction nozzle through whichthe exhaust pump draws in air, a pipe connecting the vacuum reservoirwith the suction nozzle, a spring-controlled non-return valve in thesaid pipe to prevent fluid flowing therethrough towards the reservoir,an inlet branched on to the said pipe between the said non-return valveand the suction nozzle, through which inlet atmospheric air can passdirectly to the suction nozzle, a valve seat in the said inlet facingoutwards, a valve moving inwards and outwards for opening and closingthe said inlet, an element movable in response to air pressure, a,lost-motion connection mechanically coupling the said movable element tothe valve, so that when the valve approaches its seat it will be drawnsmartly into contact therewith by suction, and when it is pulled off Iits seat it will move smartly away therefrom owing to the approximateequalization of pressure on both sides of the valve, the side of thepressureresponsive element nearer to the valve being open to atmosphericpressure, a duct establishing communication between the side of thepressure-responsive element remote from the valve and the interior ofthe reservoir, a spring tending to close the valve against the suctionof the reservoir pressure acting upon the movable element and means foradjusting the force of the spring and thereby varying the reservoirpressures at which the valve opens and closes.

4. In a device for controlling the air intake of a suction pump adaptedto be connected to a reservoir containing air at sub-atmosphericpressure, a conduit for connecting the reservoir to the suction pump, acasing forming an air intake and connected to said conduit, a valveadapted to close communication from said casing to said conduit, aspring biasing said valve to closed position, means defining a chamberwithin said casing, a duct connecting said chamber to the conduitcommunicating with the reservoir, a movable member in said chamber andexposed to the atmosphere on one side and the sub-atmospheric pressurein the reservoir on the other side and movable in response to thediiferential thereof, a rod connecting said member with said valve formoving the valve in accordance with the movement of the member, said rodhaving a channel therein for providing restricted communication ofatmospheric air to said other side of the member.

MAXIMILIANO ALVAREZ LIPKAU.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,060,964 Atwood May 6, 19131,653,110 Le Valley Dec. 20, 1927 1,968,985 Black c Aug. 7, 19342,410,522 Powell Nov. 5, 1946

